cephalalgia vs ache

cephalalgia and ache both are nouns.

Word	Noun	Adjective	Verb	Adverb
cephalalgia	Yes	No	No	No
ache	Yes	No	Yes	No

As nouns, ache is a hypernym of cephalalgia; that is, ache is a word with a broader meaning than cephalalgia:

cephalalgia: pain in the head caused by dilation of cerebral arteries or muscle contractions or a reaction to drugs
ache: a dull persistent (usually moderately intense) pain

Other hypernyms of cephalalgia include aching.

cephalalgia (noun)	ache (noun)
pain in the head caused by dilation of cerebral arteries or muscle contractions or a reaction to drugs	a dull persistent (usually moderately intense) pain

cephalalgia (verb)	ache (verb)
	have a desire for something or someone who is not present
	be the source of pain
	feel physical pain